I have a Roland kr103 the key board plays for a few minutes and then cuts out.

Yes, you can use the second pedal on a Roland BK-5 keyboard to transpose the key of the music that you are playing up or down by a semitone at a time. To do this, you will need to press and hold the second pedal while playing the keyboard. You can also use the transpose function in the settings menu of the BK-5 to adjust the key of the music that you are playing by a specific number of semitones.

If it has capacitors they are going bad...You have to buy the same kind and solder the old ones out and new ones in

It's most likely the keyboard contact strip needs cleaning or replacing.

hi there.
see if this link helps you out.
Roland xp 50 main board sound problem Google Search

EP-50's are notorious for problems with either the 4.65 voltage feed to the velocity sensitive keys or failure of the small zenner diaodes. Each key has a pair fo split circles on the circuit board under it. When you hit the key you connect each side of the circles and the harder you hit the keys the quicker the circuits close the louder the sound. Problem is if the voltage to either circle fails, due to bad solder, scratch on circuit board, failed diaode then the sound disappears. The fix is simple if you are knowledgeable on solder on circuit boards, can use a multimeter and can dissassemble and reassemble the keyboard. If you have to take it to a repair shop it is probably not worth fixing as this is not one of the better Roland products

Using keys too "hard"? If you are hitting them so hard it MAY rattle the circuit board inside and momentarily break a connection that is causing the processor to stall. This is not a good idea... Keys do NOT have to be played hard... If you are doing this as a show off thing, be prepared to pay repair bills. You can show off without putting much force on the keys. You will likely damage the aftertouch sensor by beating on the keys and also crack the circuitry that the key contacts work against requiring expensive replacement.

If these are semi weighted keys here is a cut and paste from a manual:
19. Disassembling the Keyboard Assembly
* After inserting a round stick (Rod: TX000670)
between the frame and the keys, remove the
circuit boards. (Fig. 23)
19-1 GHD EBUS L, MK SUB Circuit Board
(Time required: about 12 minutes)
Remove the seven (7) screws marked [260A]. The
GHD EBUS L and MK SUB circuit boards can then
be removed. (Fig. 24, Photo 5)
19-2 GHD M Circuit Board
(Time required: about 12 minutes)
Remove the five (5) screws marked [260B] and the
screw marked [262]. The GHD M circuit board can
then be removed. (Fig. 24)
19-3 GHD H Circuit Board
(Time required: about 12 minutes)
Remove the four (4) screws marked [260C] and the
screw marked [262]. The GHD H circuit board can
then be removed. (Fig. 24)
* Keys can be removed without removing the
circuit boards.
* After removing the GHD EBUS L, GHD M and
GHD H circuit boards, and the rubber contacts
can then be removed.
19-4 Rubber contact
Remove the GHD circuit board for the involved key.
The rubber contacts can then be removed.

The rod is inserted above the weighted hammer and the bottom of the keys from one end. It appears to be about 1/4 inch diameter dowel and will run the full length of the keyboard. You might use 3 foot ones from each end.

Screws are removed and the boards removed without taking the individual keys out.

You probably need to just clean the circuit board and the conductive rubber contacts. There are two per key to facilitate reading the key velocity.

Use 99% isoprophyl alcohol and Q-Tips to clean both the board and the rubber contacts.

A rod is inserted lengthwise to hold the hammer weights while removing the boards. Use dowels from each end inserted about halfway back between the keys and the weight rods. Use a 1/4 inch dowel rod.

You have to take out a few screws to remove the boards from the key assembly. Be careful of the cables.

You either did not get the ribbon cable seated OR got it upside down.

If this cable is the flat ribbon with exposed solder plated points of contact, OFTEN those connectors have a latch to release by GENTLY moving tabs on eaither side in the direction of pulling the cable out. This lock MUST be moved out slightly to allow the cable to seat properly. The solder plated contacts will be FULLY into the connector when seated properly.

These cables ALSO can be inserted backwards and NO connection will be made.

You need to clean the pcb and remove dried spillage residue

you could try wasking the rubber contacts but these may need to b ereaplaced.